The present invention relates to image sensors, and more specifically, to image sensors that provide vertical charge transfer.
Image sensors are commonly used in electronic devices such as cellular telephones, cameras, and computers to capture images. Color sensing schemes commonly used with conventional image sensors involve forming color filter arrays on top of the image sensors. The color filter arrays include tiles incorporating various colored dyes for color filtering. An example of a color filter array pattern that may be used is the GRGB (green-red-green-blue) Bayer pattern.
Image sensors have arrays of image sensor pixels with which the image sensor generates data corresponding to the captured images. Each respective image sensor pixel associated with a given pixel sub-array does not have the capability to differentiate among various types of light according to its wavelength. Placing color filters over the pixels allows the pixels to be sensitive to a certain range of wavelength in the visible spectrum (e.g., an image pixel is sensitive to green light, red light, or blue light). Sensing color using this approach therefore sacrifices sensitivity by absorbing light with the color filters. It would therefore be desirable to be able to provide image sensors with improved sensitivity.